A lot more than 50% of the compression and pumping systems above 3 MW require a variable-speed drive. Frequently medium-voltage motors fed by frequency converters and parallel shaft gears are chosen. Others are using epicyclic gears with a hydrodynamic superimposition drive.
Taking advantage of the state of the artwork in electrical motors and frequency converters, the driving system for the superimposition of the earth carrier is Variator Gearbox founded on a Long lasting Magnet Synchronous Superimposition (SI) electric motor and a dynamic Front-End Cycle Converter. Therefore – E means Electric.
This is a high-speed gear drive system incorporating elements that allow the use of a low-cost constant-speed (electric) driver for a variable-speed application.
A lot more than 50% of the compression and pumping systems above 3 MW require a variable-speed drive. Often medium-voltage motors fed by frequency converters and parallel shaft gears are chosen. Others are using epicyclic gears with a hydrodynamic superimposition drive.
It started with hydraulic liquid couplings creating slippage with results not much much better than the throttle.
The design of hydraulic clutches then improved and included a torque converter and a superimposed epicyclic drive.
Adjustable Frequency Drives (VFD) were developed and, at the same time, the price of the shaft trains increased, and so did efficiency. The problem of THD (Total Harmonic grid Distortion) rose and held VFD out of many applications.
Taking advantage of the condition of the artwork in electric motors and frequency converters, the driving system for the superimposition of the planet carrier is founded on a Long term Magnet Synchronous Superimposition (SI) engine and a dynamic Front-End Cycle Converter. Therefore – E stands for Electric.
That is a high-speed gear drive system incorporating parts that 
allow the use of a low-cost constant-speed (electric) driver for a variable-speed application.
All of the over plots were taken by analyzing the current to the motor. In a normal scenario, the vibration will be monitored and kept on a periodic basis. If the 360 Hz signal is present in the vibration spectrum, it isn’t normally of any concern. If, however, additional unexplained frequencies appear in the vibration spectra, then it might be advisable to check out both the current waveform and the existing spectrum. In the web pages that follow, some examples of problems found out in DC drives and motors are presented.”
It started with hydraulic liquid couplings generating slippage with results very little better than the throttle.
The design of hydraulic clutches then improved and included a torque converter and a superimposed epicyclic drive.
Adjustable Frequency Drives (VFD) were developed and, at the same time, the cost of the shaft trains increased, therefore did efficiency. The problem of THD (Total Harmonic grid Distortion) rose and kept VFD out of many applications.